In general, an outlet is coupled to a plug of an electric or electronic appliance to supply power to the electric or electronic appliance through the plug. Such outlets may be embedded in walls of various buildings, and may be integrated to form a portable power strip.
Typically, an outlet has insertion holes in its front surface to receive connecting pins of a plug. Connecting terminals, which are connected to a power source and contact the connecting pins to transmit current, are fixed to the inner portion of the outlet below the insertion holes. When the connecting pins of the plug are inserted through the insertion holes, the connecting pins physically contact the connecting terminals to transmit current.
However, in this case, the plug should be pushed to the outlet to couple the plug to the outlet, and the plug should be pulled out of the outlet to decouple the plug from the outlet. When the plug is removed from the outlet, the outlet may be broken due to excessive pulling force or unintended locking in the outlet.
Furthermore, since a foreign material such as a chop stick or a nail can be easily inserted into insertion holes of a typical outlet, children may be exposed to danger from electric shock, and dust or moisture may be introduced to cause an electric leak and a short circuit.